Research in colorectal cancer
We are always learning more about cancer. Researchers and healthcare professionals use what they learn from research studies to develop better practices that will help prevent, find and treat colorectal cancer. They are also looking for ways to improve the quality of life of people with colorectal cancer.
The following is a selection of research showing promise for colorectal cancer. We’ve included information from PubMed, which is the research database of the National Library of Medicine. Each research article in PubMed has an identity number (called a PMID) that links to a brief overview (called an abstract). We have also included links to abstracts of the research presented at meetings of the American Society of Clinical Oncology (ASCO), which are held throughout the year. You can find information about ongoing clinical trials in Canada from CanadianCancerTrials.ca and ClinicalTrials.gov. Clinical trials are given an identifier called a national clinical trial (NCT) number. The NCT number links to information about the clinical trial.
Reducing the risk of colorectal cancer
Some substances or behaviours may prevent or lower your risk of developing colorectal cancer. The following is noteworthy research into ways to lower your risk.
Acetylsalicylic acid (ASA, Aspirin, salicylate) and other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Motrin, Advil, Nuprin) and naproxen (Naprosyn), are linked to a lower risk of developing colorectal cancer (Cancer Epidemiology, Biomarkers & Prevention, PMID 25613116; International Journal of Cancer, PMID 24599876). Aspirin and other NSAIDs may even help prevent colorectal cancer from coming back (recurring) (ASCO, Abstract 3504). Research also shows that people who have a certain genetic makeup (called a genotype) may benefit more than others from taking Aspirin and other NSAIDs to lower their risk for colorectal cancer (JAMA, PMID 25781442). These drugs may also prevent people who had colorectal neoplasia from developing another neoplasia or colorectal cancer (BMJ, PMID 27919915). More research is needed to further our understanding of the role that Aspirin and other NSAIDs may play in preventing colorectal cancer (Current Pharmacology Reports, PMID 26688785).
Statins are drugs that lower cholesterol levels in the body. Some research suggests that statins may lower the risk for colorectal cancer (World Journal of Gastroenterology, PMID 24587664; Cancer Causes & Control, PMID 24265089; Cancer Epidemiology, PMID 27750068). There is some evidence that statins may help lower the risk of colorectal cancer in people with inflammatory bowel disease (Clinical Gastroenterology and Hepatology, PMID 26905907).
High amounts of calcium and vitamin D from your diet or supplements may lower the risk of developing colorectal cancer (International Journal of Cancer, PMID 27466215, PMID 24623471; Journal of Cancer, PMID 26918035). Other studies found that taking calcium supplements, vitamin D supplements or both may lower the risk of developing adenomas in the colon and rectum (World Journal of Gastroenterology, PMID 27182169; International Journal of Cancer, PMID 25156950). But some research shows that taking supplements does not lower risk (New England Journal of Medicine, PMID 26465985).
Find out more about research in cancer prevention.
Screening tests help find colorectal cancer before any signs or symptoms develop. When cancer is found and treated early, the chances of successful treatment are better. The following is noteworthy research into screening for colorectal cancer.
Stool DNA testing is a promising way to screen for colorectal cancer (Journal of Gastrointestinal Cancer, PMID 26922358; New England Journal of Medicine, PMID 24645800). It finds DNA markers in cells that are shed into the stool from precancerous adenomas and cancerous tumours in the colon. People may find the stool DNA test easier to do than other screening tests for colorectal cancer because a colonoscope isn’t inserted into the intestine and you don’t need to clear the intestine (called bowel preparation) or restrict your diet before the test. The stool DNA test may find some types of adenomas in the colon better than other stool tests used in colorectal cancer screening, such as the fecal immunochemical test (FIT) and fecal occult blood test (FOBT) (World Journal of Gastrointestinal Oncology, PMID 27190584; PLoS One, PMID 24465639). The US approved the Cologuard stool DNA test as a screening test for colorectal cancer, but it hasn’t been approved for use in Canada yet.
Virtual colonoscopy (also called CT colonography) uses a CT scan to create images of the colon. It is less invasive and more comfortable than a regular colonoscopy because a colonoscope isn’t inserted into the intestine. Some drawbacks of this test are exposure to radiation, having to travel to centres that have the equipment and the fact that CT scan can’t find very small polyps. More research is needed to find out what role virtual colonoscopy may have in screening for colorectal cancer (Clinical Radiology, PMID 26145187; Journal of the National Comprehensive Cancer Network, PMID 26285241).
Capsule endoscopy (also called PillCam colon endoscopy or capsule colonoscopy) may be used as a screening test for colorectal cancer. In this test, the person needs to clear the intestine and then swallow a tiny pill (capsule) containing a camera. The camera takes pictures as it moves through the digestive tract and is passed from the body. Doctors look at the pictures to see if there are any polyps or other abnormal areas in the colon or rectum. Studies show that capsule endoscopy works best to examine the lining of the colon when it has been thoroughly cleansed. Capsule endoscopy does not seem to be as good as colonoscopy at finding polyps or abnormalities. Most research suggests that capsule endoscopy is best used after a positive stool screening test such as FOBT or FIT. It may also be a good alternative to regular colonoscopy in people who can’t have the procedure (Annals of Translational Medicine, PMID 27867950; Clinical Gastroenterology and Hepatology, PMID 27165469, PMID 26133904; Gastroenterology, PMID 25620668).
Blood tests for colorectal cancer screening are starting to become available in Canada and are an attractive alternative to screening with stool samples that you have to collect at home. These blood tests look for certain biomarkers in the blood. When there is a change in the amount of a biomarker, it may mean the person has cancer or a precancerous condition. A positive blood test result may suggest that you have a higher than average risk of developing colorectal cancer. Blood tests aren’t currently part of provincial and territorial colorectal cancer screening programs. Sept9 is an example of blood tests that researchers are studying for colorectal cancer screening and diagnosis. When used with a stool test, such as FIT, Sept9 seems to enhance screening (Cancer Biomarkers, PMID 28128742; Clinical and Translational Gastroenterology, PMID 28102859). Sept9 may also be effective in predicting prognosis and monitoring response to treatment, but more research is needed.
Find out more about research in screening and finding cancer early.
Diagnosis and prognosis
A key area of research looks at better ways to diagnose and stage (how far the cancer has spread) colorectal cancer. Researchers are also trying to find ways to help doctors predict a prognosis (the probability that the cancer can be successfully treated or that it will come back after treatment). The following is noteworthy research into diagnosis and prognosis.
Biomarkers are substances, such as proteins, genes or pieces of genetic material like DNA and RNA, that are found naturally in the body. They can be measured in body fluids like blood and urine or tissue that has been removed from the body. A gene mutation or a change in the normal amount of a biomarker can mean that a person has a certain type of cancer. Biomarkers can also help doctors predict the prognosis or response to treatment in people with colorectal cancer. Researchers are looking at the following biomarkers to see if they can help doctors diagnose, predict a prognosis for and find out which treatments will benefit a person with colorectal cancer:
- microRNA, which are short pieces of RNA that control cell growth and death (Biomedicine & Pharmacotherapy, PMID 27701052; International Journal of Molecular Sciences, PMID 26602923)
- circulating nucleosomes, which are DNA wrapped around proteins (Cancers, PMID 28075351)
- tumour endothelial markers, which are proteins in cells that line the blood vessels of a tumour (Disease Markers, PMID 27965519)
Being physically active may improve prognosis. Researchers found that people who were physically active before and after a diagnosis of colorectal cancer had a lower risk of dying from the disease than those who aren’t physically active (Oncotarget, PMID 27437765). A phase III clinical trial is looking at the physical activity levels and disease-free survival of people who have been treated for stage 2 or stage 3 colon cancer. The trial is trying to find out how effective it is to give health education materials along with a physical activity program compared to only giving health education materials (CanadianCancerTrials.ca, NCT00819208).
Find out more about research in diagnosis and prognosis.
Researchers are looking for new ways to improve treatment for colorectal cancer. Advances in cancer treatment and new ways to manage the side effects from treatment have improved the outlook and quality of life for many people with cancer.
The following is noteworthy research into surgery for colorectal cancer.
Laparoscopic surgery uses a thin, tube-like instrument with a light and camera (called a laparoscope) to remove tissue or organs through small surgical cuts (incisions) in the body. Researchers want to find out if laparoscopic surgery to remove rectal cancer is a good alternative to surgery through a larger cut in the abdomen (called open surgery). Laparoscopic surgery is linked with less blood loss and shorter hospital stays compared to open surgery. So far results show that laparoscopic surgery is just as effective in removing the tumour and preventing recurrence as open surgery. (International Journal of Colorectal Disease, PMID 26847617, PMID 26137968; JAMA, PMID 26441180; New England Journal of Medicine, PMID 25830422).
Radiation therapy and chemotherapy
The following is noteworthy research into radiation therapy and chemotherapy for colorectal cancer.
Intraoperative radiation therapy (IORT) gives radiation therapy during surgery. It allows doctors to deliver higher doses of radiation to the cancer than conventional radiation therapy. Research shows that IORT helps control the growth of the cancer. It also improves survival in people with colorectal cancer that has spread to tissues or lymph nodes close to where the tumour started (called locally advanced cancer). It seems that IORT is most effective when the cancer can’t be completely removed by surgery or when there are positive surgical margins (Radiation Oncology, PMID 28077144; Journal of Surgical Oncology, PMID 24510523).
Radioembolization (also called selective internal radiation therapy) is a procedure that delivers radiation directly to tumours using tiny radioactive beads called microspheres. Microspheres contain a radioactive material such as yttrium-90. A catheter carries the microspheres through the hepatic artery to the liver, and they deliver radiation only to the tumour. They also block the blood supply to the tumour so the cancer can’t get the oxygen and nutrients it needs to grow. Most research so far has looked at using radioembolization to treat liver metastases in people whose colorectal cancer didn’t respond to many chemotherapy treatments or who can’t have surgery (European Radiology, PMID 27059858; Annals of Surgical Oncology, PMID 25323474; Journal of Cancer Research and Clinical Oncology, PMID 24318568). Researchers are also studying radioembolization in combination with chemotherapy as the first treatment for people with liver metastases. This combination of treatments seems to improve progression-free survival (Current Treatment Options in Oncology, PMID 27098532).
Neoadjuvant treatment using chemoradiation is a standard treatment for rectal cancer. Neoadjuvant means that the treatment is given before surgery. A clinical trial is comparing standard neoadjuvant chemoradiation for rectal cancer to neoadjuvant chemotherapy with FOLFOX, which is leucovorin (folinic acid), 5-fluorouracil (Adrucil, 5-FU) and oxaliplatin (Eloxatin). Researchers are trying to find out which treatment has better survival, fewer side effects and the best surgical outcomes (CanadianCancerTrials.ca, NCT01515787).
The following is noteworthy research into targeted therapy for colorectal cancer.
Ramucirumab (Cyramza) is a type of anti-angiogenesis drug that blocks a substance called vascular endothelial growth factor (VEGF). Researchers are studying ramucirumab as a second-line therapy along with FOLFIRI, which is leucovorin, 5-fluorouracil and irinotecan (Camptosar), in people with metastatic colorectal cancer. A phase III study found that people who were given ramucirumab and FOLFIRI survived longer than those who were given a placebo and FOLFIRI (Annals of Oncology, PMID 27573561; Lancet Oncology, PMID 25877855).
Find out more about research in targeted therapy.
Learn more about cancer research
Researchers continue to try to find out more about colorectal cancer. Clinical trials are research studies that test new ways to prevent, detect, treat or manage colorectal cancer. Clinical trials provide information about the safety and effectiveness of new approaches to see if they should become widely available. Most of the standard treatments for colorectal cancer were first shown to be effective through clinical trials.
Abnormal and uncontrolled growth of cells.
A non-cancerous, or benign, tumour or growth that starts in epithelial cells that line the inside of organs and glands. Adenomas may become cancerous if they are not treated.
An adenoma may be called an adenomatous polyp when it is in the gastrointestinal (GI) tract.
The molecules inside the cell that program genetic information. DNA determines the structure, function and behaviour of a cell.
A procedure that uses an endoscope (a thin, tube-like instrument with a light and lens) to examine or treat the colon.
Cells or tissue may be removed for examination under a microscope. Doctors may also use colonoscopy to control bleeding or remove polyps.
The type of endoscope used for this procedure is called a colonoscope.
Any cellular, molecular, chemical or physical change that can be measured and used to study a normal or abnormal process in the body. Biomarkers are used to check the risk for, presence of or progress of a disease or the effects of treatment.
For example, prostate-specific antigen (PSA) can be used as a biomarker for prostate cancer or blood sugar levels can be used to monitor diabetes.
Also called biological marker (a molecular biomarker may be called molecular marker or signature molecule).
The area of normal tissue surrounding a tumour that is removed along with the tumour during surgery.
The margin may be described as negative or clean if no cancer cells are found at the edge of the tissue. It may be described as positive or involved if cancer cells are found at the edge of the tissue, which suggests that not all of the cancer was removed.
The amount of time after treatment that a person lives with a disease (such as cancer) without the disease getting worse.
Researchers may measure progression-free survival in clinical trials to find out how well a treatment works.
Treatment that combines chemotherapy with radiation therapy. Chemotherapy is given during the same time period as radiation therapy. Some types of chemotherapy make radiation therapy more effective.
Also called chemoradiotherapy.
A process that slows or stops the growth of new blood vessels that a tumourneeds to grow and survive.
Treatment given for a condition or disease (such as cancer) when the first-line therapy (the first or standard treatment) does not work or stops working.
Also called secondary therapy or secondary treatment.